Polyolefin resins are known in the art as having desirable qualities such as ease of processability, chemical resistance, weather resistance, and insulating characteristics. Polyolefins have been utilized very often in various fields.
However, polyolefin resins have also been known to include drawbacks inasmuch as they are generally readily combustible, and when burned, can liquefy due to thermal decomposition, whereby polyolefins can drip the ignited or non-ignited droplets. The presence or absence of a drip is one of the important factors in evaluating flame retardant properties of resins. If dripping is present upon burning, flame retardant properties are considered low, even when self-extinguishing properties are present. It is desirable to reduce dripping and provide compositions with high char formation upon burning. Various approaches have been taken in the prior art in order to render polyolefins more resistant to burning. Flame retardant materials such as halogenated additives, chemical char producers, and chemical water generators have been added to polyolefin compositions.
U.S. Pat. No. 4,101,498 relates to a reportedly oil-resistant, fire-resistant polymer composition which is reportedly useful in coating electrical conductors. The composition comprises a block copolymer, extending oil, polymeric alpha-olefin, filler and fire retardant package comprising antimony trioxide, an adduct of hexachlorocyclo-pentadiene and a zinc borate.
U.S. Pat. No. 4,622,350 relates to a resin composition comprising polypropylene, a hydrogenated mono alkylarene-conjugated diene block copolymer, a functionalized low molecular weight polypropylene wax, oil, and a hydrated organic filler which reportedly can be blended to form a self-extinguishing, low smoke and halogen free insulation composition which exhibits high ultimate elongation and reportedly is relatively easy to process.
U.S. Pat. No. 4,710,317 relates to a reportedly flame retardant polyolefin resin composition which, when molded, reportedly affords a molded product having highly flame retardant properties, no dripping properties, a smooth surface and an excellent appearance and superior resistances to heavy metal deterioration, heat deterioration and weather, which composition consists of (A) 5-60% by weight of a halogen-containing flame retardant, (B) 100-10% by weight of antimony trioxide based on the weight of the halogen-containing flame retardant, (C) 0.5-15% by weight of a crosslinking agent, (D) 0.05-5% by weight of a specified thiophosphite, and (E) the balance % by weight of a polyolefin resin, the total of the quantities (A), (B), (C), (D) and (E) being 100% by weight. If necessary, a processing aid may be further added to the above flame retardant polyolefin resin composition.
U.S. Pat. No. 5,777,031 relates to a thermoplastic elastomer composition comprising a block copolymer having at least two resinous end blocks and a high 1.2-addition butadiene midblock, a paraffin oil and a crystalline polyolefin. The composition reportedly exhibits greater softness, better processability and better elastic properties as compared with similar compositions made with normal amounts of a 1.2-addition. Compositions are reportedly useful for utilities such as overmolding into hard substrates, grips, medical tubing and miscellaneous rubbery articles.
U.S. Pat. No. 6,395,839 relates to a bulk polymerized grafted and crosslinkable thermoplastic polyolefin powder composition which is in the form of a powder intended for the production of flexible coatings by free flow over a hot mold, characterized in that it contains: (a) from 100 to 5% by weight and preferably from 80 to 20% by weight of at least one homopolymer of ethylene and/or at least one copolymer containing at least 50 molar % of ethylene; (b) from 0 to 95% by weight and preferably from 20 to 80% by weight of at least one thermoplastic elastomer; and from 0.1 to 15 parts by weight and preferably from 0.5 to 10 parts by weight of a grafting agent, per 100 parts by weight of the accumulated components “a” and “b”. This powder composition reportedly is suitable for the production of flexible coatings by its free flow over a hot mold.
U.S. Pat. No. 6,414,070 relates to nanocomposite compositions comprising organically modified clays and polyolefins or copolymers containing repeat units derived from olefins reportedly having flame retardant or flame resistant properties. Sheets and laminates of the nanocomposite reportedly can be utilized wherever flame retardant properties are desired.
U.S. Pat. No. 6,599,963 relates to a method of reportedly flame retarding a polymeric substrate by adding thereto an effective flame retarding amount of a selected hindered amine compound; and a method of reportedly flame retarding a polymeric substrate by adding thereto an effective flame retarding amount of a synergistic mixture of a selected hindered amine compound and an organic or inorganic flame retardant which contains bromine and/or phosphorus moieties.
U.S. Pat. No. 6,610,770 relates to polymer compositions having flame retardant properties that are made from a polymer blend using a defined process with a smectite clay that has been reacted with a specified mixture of organic materials. These compositions have the property that when the organically modified clay is added to the polymer, a composite results which reportedly has flame-retardant properties.
U.S. Application Publication No. 2006/0128870 relates to compositions comprising a polymeric matrix; a plurality of fillers; and a block copolymer wherein at least one segment of the block copolymer interacts with the fillers. It also relates to compositions comprising a plurality of fillers having surfaces and a block copolymer wherein at least one segment of the block copolymer is reportedly capable of interacting with the fillers upon application in a polymeric matrix. Compositions comprising a flame retardant compound and a block copolymer wherein at least one segment of the block copolymer is reportedly capable of interacting with the flame retardant compound upon application in a polymer matrix are also provided.
International Publication No. WO 02/094920 relates to a nanocomposite composition of from 1 to 30 weight percent hydrogenated C9 aromatic polymer, from 1 to 30 weight percent cation exchanging layered silicate material, and from 98 to 40 weight percent polyolefin, the hydrogenated C9 aromatic polymer and the cation exchanging layered silicate material being dispersed in the polyolefin polymer. It also relates to a method for making such nanocomposition by blending the hydrogenated C9 aromatic polymer, the cation exchanging layered silicate material and the polyolefin at a temperature sufficiently high to melt or soften the polyolefin polymer.
International Publication No. WO 2006/071833 relates to a blend of nanocomposites with a polyolefin nanocomposite preferably serving as a continuous phase and a polyamide nanocomposite preferably serving as a discontinuous phase. The exfoliated nanoclay in both nanocomposites reportedly contributes stiffness, toughness and flame retardancy to the blend. Other optional ingredients include conventional essentially halogen-free flame retardants, intumescent essentially halogen-free flame retardants, and other typical polymer compounding additives. The compound reportedly can be processed as a thermoplastic.
Japanese Publication No. 59-074142 relates to a flame retardant resin composition reportedly having a dripping inhibiting property during combustion, consisting of polypropylene, an inorganic filler, an organic halide flame retarder, a styrene/butadiene rubber and a specified glow time shortening agent.
Japanese Publication No. 08-073684 involves obtaining a composition reportedly suitable for a household appliance and an office automation device material, comprising a styrenic resin, a specific bromine-based flame-retardant, antimony trioxide and a styrene-butadiene copolymer.
Japanese Publication No. 10-279747 relates to a composition reportedly capable of stopping slippage of molding material by fusing to polyolefin molding material which is liable to slip by adding a mineral oil and polypropylene to a styrene-based block copolymer elastomer.
Japanese Publication No. 2000-080210 relates to a halogen-free elastomer composition reportedly having flexibility and elasticity while maintaining heat resistance and abrasion resistance of a composition containing an olefin-based elastomer and a flame retardant suitable for a part material of a wire harness, etc.
Japanese Publication No. 2001-270967 relates to an olefin elastomer composition that reportedly has flame resistance equal to that of polyvinyl chloride and can reportedly satisfy requirements on abrasion resistance as a protective tube or sheet for a wiring harness of a vehicle.
Japanese Publication No. 2004-018300 relates to a reportedly fire-resistant optical fiber core wire which reportedly has excellent mechanical characteristics and fire-resistance and can be used at a high temperature and under high humidity and reportedly where there is very little protruding of an optical fiber at the time of practical use.